A remarkable metal-oxidant-solvent- and base-free domino route for the regioselective access to a wide breadth of 2,4-di- and 2,3,4/6-trisubstituted pyridines including carbo- and heterocyclic fused ones is reported. This [3C+2C+1N]...

An efficient pyrrolidine : 4-ClBzOH salt (catalyst IV) catalyzed [3 + 3] cyclization reaction of β-alkyl-substituted nitroalkenes as 1,3-binucleophiles with various β-aryl/alkyl/ alkenyl-substituted acroleins in an open-atmosphere is reported. Eventually, this tunable organocatalytic reaction creates one CÀ C and C=C bonds selectively that turns out to have a wide substrate scope, which affords a series of substituted nitroarenes in good to high yields. In addition, several other positive features are associated with this organocatalytic approach such as evading toxic metalcatalysts, no need for external oxidant and nitrating agent, 100% carbon-economical, excellent tolerance of functionalities, water as a sole by-product, circumventing of prefunctionalized arenes etc. Moreover, a range of important hetero-and carbocycles such as 2-arylcarbazole, 2,6-diphenylindole, 2'-chloro-1,1' : 4',1''-terphenyl and 1 : 1' : 4',1''-terphenyl were accessed from nitroarenes through our unique methods.

Remarkable organobase-controlled selective synthesis of a wide breadth of valuable 2,5-diaryl-4-nitrobenzoates and 1-hydroxy-4-oxocyclohexencarboxylates bearing a tetra-substituted stereogenic carbon is reported. This one-pot cyclization reaction operates between a bunch of 3-nitroallylarenes and β,γ-unsaturated α-ketocarbonyls by carefully choosing DBU or DABCO as an organobase under aerobic conditions. Notably, as a nucleophilic base, DABCO favours the Nef-reaction over the dehydration-aerial oxidation process, aiming for unexpected cyclohexanone architectures. Moreover, this operationally simple technique holds a few positive qualities: good yields with diastereoselectivities (dr≤91:9), broad substrate scope, no added oxidant, excellent functional group compatibility, 100% carbon-economical etc. Furthermore, the obtained 4-nitrobenzoate framework has been utilized for the synthesis of a range of valuable compounds such as 2-phenylcarbazole-3-carboxylate, 3-bromoaniline derivative, 2,5-diphenylbenzoic acid etc.